CN108137923B

CN108137923B - Dry mix mixture

Info

Publication number: CN108137923B
Application number: CN201680059945.8A
Authority: CN
Inventors: 小田尚史; 金子直树; 加藤智则
Original assignee: Mitsubishi Gas Chemical Co Inc
Current assignee: Mitsubishi Gas Chemical Co Inc
Priority date: 2015-12-28
Filing date: 2016-12-19
Publication date: 2021-01-01
Anticipated expiration: 2036-12-19
Also published as: EP3398995A4; EP3398995B1; JPWO2017115685A1; TWI717443B; EP3398995A1; JP6981255B2; US20190010328A1; KR102621631B1; KR20180099633A; TW201736434A; CN108137923A; WO2017115685A1

Abstract

A dry-blended mixture of a specific m-xylylene group-containing polyamide (A) and a specific aliphatic polyamide (B), wherein the mass ratio (A)/(B) of the m-xylylene group-containing polyamide (A) to the aliphatic polyamide (B) is in the range of 55/45-65/35.

Description

Dry mix mixture

Technical Field

The present invention relates to a dry-blended mixture, and more particularly to a dry-blended mixture of a polyamide containing m-xylylene.

Background

In order to protect contents from various distribution, preservation in a refrigerator, heat sterilization, and other treatments, packaging materials used for packaging foods, beverages, and the like are required to have not only functions such as strength, resistance to cracking, and heat resistance, but also various functions such as excellent transparency, which enables contents to be recognized. Further, in recent years, gas barrier properties for preventing oxygen from entering from the outside in order to suppress oxidation of foods, and barrier properties for various aroma components accompanying a change in preference have been demanded.

As a packaging material having gas barrier properties, a multilayer film using a gas barrier resin such as polyvinylidene chloride (PVDC), ethylene-vinyl alcohol copolymer (EVOH), polyamide for a gas barrier layer is used. Among the polyamides, a polyamide containing an m-xylylene group, which is obtained by polycondensation of m-xylylenediamine and an α, ω -aliphatic dicarboxylic acid having 6 to 12 carbon atoms, has the following characteristics: when boiling treatment or retort treatment is performed, the gas barrier properties are less degraded and recovery of the gas barrier properties is rapid as compared with other gas barrier resins. In particular, m-xylylene adipamide (MXD6) which uses adipic acid as an α, ω -aliphatic dicarboxylic acid having 6 to 12 carbon atoms has recently been used in the field of packaging by taking advantage of this characteristic.

However, MXD6 has a high elastic modulus, but has low stretchability and flexibility required for film and sheet applications. Therefore, when MXD6 is applied to a film or sheet, impact resistance, pinhole resistance, shrinkage performance, and the like may be reduced. Further, when MXD6 is molded into a film or sheet, there is a problem that the molding range becomes very narrow, the moldability is poor, and the productivity is affected, and this is remarkable particularly in the case of having a stretching step.

Further, patent document 1 discloses: a polyamide filament obtained by blending MXD6 with an aliphatic polyamide for the purpose of improving the flexural rigidity of MXD 6.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-058144

Disclosure of Invention

Problems to be solved by the invention

The object of the present invention is to provide a polyamide mixture which can produce a polyamide film packaging material having excellent gas barrier properties, transparency and toughness.

Means for solving the problems

In order to solve the above problems, the present inventors tried to melt-blend nylon 6/66 into MXD6 to form a film for the purpose of improving toughness of MXD 6. However, the resin pressure and the like during film forming are unstable and cause fluctuation, and it is difficult to obtain a film having stable quality. Further, although the elongation of the film was improved, it was found that the gas barrier property was poor due to the molding processing conditions, and the performance of the obtained film was insufficient.

As a result of intensive studies, the present inventors have found that a film excellent in stable gas barrier properties, transparency and toughness can be obtained by molding a film using a mixture obtained by dry-blending MXD6 and nylon 6/66 at a specific mass ratio. The present invention has been completed based on such findings.

The present invention relates to the following <1> to <13 >.

<1> a dry-blended mixture comprising (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide, wherein the mass ratio ((A)/(B)) of the (A) polyamide containing m-xylylene to the (B) aliphatic polyamide is in the range of 55/45 to 65/35,

the m-xylylene group-containing polyamide (A) contains: a diamine unit containing 80 mol% or more of an m-xylylenediamine unit with respect to the diamine unit, and a dicarboxylic acid unit containing 80 mol% or more of at least 1 unit selected from the group consisting of an α, ω -linear fatty acid dicarboxylic acid unit having 6 to 12 carbon atoms and an isophthalic acid unit with respect to the dicarboxylic acid unit, and the molar ratio of the α, ω -linear aliphatic dicarboxylic acid unit to the isophthalic acid unit (α, ω -linear aliphatic dicarboxylic acid unit/isophthalic acid unit) is 80/20 to 100/0;

the aliphatic polyamide (B) contains 75 to 95 mol% of aminocaproic acid units and 25 to 5 mol% of hexamethylene adipamide units, based on the total structural units of the aliphatic polyamide.

<2> the dry mix according to <1> above, wherein a melting point peak (Tm (A, M)) of the M-xylylene group-containing polyamide (A) measured by differential scanning calorimetry and a melting point (Tm (A)) of the M-xylylene group-containing polyamide (A) before dry mixing measured by differential scanning calorimetry satisfy the following relationship (1), and a melting point peak (Tm (B, M)) of the aliphatic polyamide (B) before dry mixing measured by differential scanning calorimetry and a melting point (Tm (B)) of the aliphatic polyamide (B) before dry mixing satisfy the following relationship (2),

Tm(A)-3≤Tm(A，M)≤Tm(A) (1)

Tm(B)-3≤Tm(B，M)≤Tm(B) (2)。

<3> the dry-blended mixture according to <2>, wherein the melting point peak (Tm (A, M)) of the M-xylylene group-containing polyamide (A) is in the range of 225 to 237.5 ℃, and the melting point peak (Tm (B, M)) of the aliphatic polyamide (B) is in the range of 195 to 199 ℃.

<4> the dry mix mixture according to any one of <1> to <3>, wherein a difference between the relative viscosity of (A) the m-xylylene group-containing polyamide and the relative viscosity of (B) the aliphatic polyamide is in a range of 0.6 to 1.6.

<5> the dry mix according to any one of <1> to <4>, which further comprises 300 to 4000 mass ppm of a compatibility inhibitor with respect to 100 mass parts of the total amount of the (A) m-xylylene group-containing polyamide and the (B) aliphatic polyamide.

<6> the dry mix mixture according to <5> above, wherein the aforementioned compatibility inhibitor is at least 1 selected from the group consisting of sodium acetate and calcium hydroxide.

<7> the dry mix mixture according to any one of <1> to <6> above, comprising: ethylene bis (stearamide) or calcium stearate 100 to 4000 mass ppm and a nonionic surfactant 30 to 800 mass ppm,

ethylene bis (stearamide) or calcium stearate is spread on the dry mix by means of a non-ionic surfactant.

<8> A process for producing a dry-blended mixture, which comprises the step of dry-blending (A) particles (pellet) of a m-xylylene group-containing polyamide and (B) particles (pellet) of an aliphatic polyamide in such a manner that the mass ratio ((A)/(B)) of the m-xylylene group-containing polyamide to the aliphatic polyamide (B) is in the range of 55/45 to 65/35,

<9> the method of producing a dry-blended mixture according to <8>, wherein in the step of dry-blending, 300 to 4000 ppm by mass of a compatibilization inhibitor is added to 100 parts by mass of the total amount of the (A) m-xylylene group-containing polyamide and the (B) aliphatic polyamide.

<10> the method for producing a dry blended mixture according to <8> or <9>, wherein the step of dry blending comprises the following steps: 30 to 800 ppm by mass of a nonionic surfactant is added to 100 parts by mass of the total amount of (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide, and then 100 to 4000 ppm by mass of ethylene bis (stearamide) or calcium stearate is added to 100 parts by mass of the total amount of (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide.

<11> a molded article of a dry-blended mixture, wherein a microphase-separated structure is present in a molded article obtained by melt-blending the dry-blended mixture of any one of <1> to <7 >.

<12> the molded article of the dry-blended mixture according to <11>, wherein the microphase-separated structure has a columnar structure,

the columnar domains of the columnar structure are (B) aliphatic polyamide,

the diameter of the columnar crystal domain is 100 to 200nm,

the MD length of the columnar crystal domain is longer than the TD length,

the average MD length of the columnar domains is 200nm to 3 μm.

<13> a film or sheet comprising a layer formed of the dry-blended mixture as stated in any one of <1> to <7 >.

ADVANTAGEOUS EFFECTS OF INVENTION

The dry-blended mixture of the present invention can provide a polyamide film excellent in gas barrier properties, transparency and toughness.

Drawings

Fig. 1 is an SEM photograph for observing the morphology of the gas barrier layer of the multilayer thin film obtained in example 5, and is a photograph for measuring the MD-direction length of the columnar crystal domains.

Fig. 2 is an SEM photograph for observing the morphology of the gas barrier layer of the multilayer thin film obtained in example 5, and is a photograph for measuring the average diameter (TD direction) of the columnar domains.

Detailed Description

The dry mix of the present invention is described in detail below. In the present specification, the preferable limitations may be arbitrarily adopted, and combinations of the preferable modes are more preferable.

The dry-blended mixture of the present invention is a dry-blended mixture of (A) a metaxylylene group-containing polyamide and (B) an aliphatic polyamide, wherein the mass ratio ((A)/(B)) of the metaxylylene group-containing polyamide to the aliphatic polyamide (B) is in the range of 55/45 to 65/35.

((A) m-xylylene group-containing polyamide)

The m-xylylene group-containing polyamide used in the present invention contains: a diamine unit containing 80 mol% or more of a m-xylylenediamine unit relative to the diamine unit; and a dicarboxylic acid unit comprising 80 mol% or more of at least 1 unit selected from the group consisting of an alpha, omega-linear aliphatic dicarboxylic acid unit having 6 to 12 carbon atoms and an isophthalic acid unit relative to the dicarboxylic acid unit, wherein the molar ratio of the alpha, omega-linear aliphatic dicarboxylic acid unit to the isophthalic acid unit (alpha, omega-linear aliphatic dicarboxylic acid unit/isophthalic acid unit) is 80/20 to 100/0.

From the viewpoint of gas barrier properties, the diamine unit constituting the m-xylylene group-containing polyamide contains 80 mol% or more of the m-xylylenediamine unit relative to the diamine unit, preferably 90 mol% or more, more preferably 95 mol% or more, and even more preferably substantially 100 mol%.

In the m-xylylene group-containing polyamide, as a compound capable of constituting a diamine unit other than the m-xylylenediamine unit, there can be exemplified: diamines having an alicyclic structure, such as diamines having an aromatic ring, e.g., p-xylylenediamine, 1, 3-bis (aminomethyl) cyclohexane, and 1, 4-bis (aminomethyl) cyclohexane; aliphatic diamines such as tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, 2-methyl-1, 5-pentanediamine, polyoxyalkyleneamine, and polyetherdiamine, but are not limited thereto.

From the viewpoint of crystallinity, the dicarboxylic acid unit constituting the isophthalyl group-containing polyamide contains at least 1 unit selected from the group consisting of an α, ω -linear fatty acid dicarboxylic acid unit having 6 to 12 carbon atoms and an isophthalic acid unit in an amount of 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably substantially 100 mol% relative to the dicarboxylic acid unit.

Examples of the compound constituting the α, ω -straight-chain fatty acid dicarboxylic acid unit having 6 to 12 carbon atoms include: adipic acid, suberic acid, azelaic acid, sebacic acid, lauric acid, and the like, and from the viewpoint of gas barrier properties and crystallinity, adipic acid and sebacic acid are preferable, and adipic acid is more preferable.

Isophthalic acid can easily give a polyamide excellent in gas barrier performance, and does not inhibit the polycondensation reaction in the production of an isophthaloyl group-containing polyamide, and therefore, can be suitably used for producing an isophthaloyl group-containing polyamide.

In the dicarboxylic acid unit constituting the isophthalic-group-containing polyamide, the molar ratio of the α, ω -linear aliphatic dicarboxylic acid unit to the isophthalic acid unit (α, ω -linear aliphatic dicarboxylic acid unit/isophthalic acid unit) is 80/20 to 100/0, preferably 85/15 to 100/0, and more preferably 90/10 to 100/0, from the viewpoint of lowering the glass transition temperature of the polyamide and imparting flexibility to the polyamide.

Examples of compounds other than the α, ω -straight chain fatty acid dicarboxylic acid unit having 6 to 12 carbon atoms and the isophthalic acid unit, which may constitute a dicarboxylic acid unit, include: alicyclic dicarboxylic acids such as 1, 3-cyclohexanedicarboxylic acid and 1, 4-cyclohexanedicarboxylic acid; aromatic dicarboxylic acids other than isophthalic acid such as terephthalic acid, phthalic acid, xylylene dicarboxylic acid, and naphthalenedicarboxylic acid, but the present invention is not limited thereto.

In addition, as the copolymer unit constituting the m-xylylene group-containing polyamide, in addition to the diamine unit and the dicarboxylic acid unit, it is possible to use: lactams such as caprolactam and laurolactam; aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid; an aromatic aminocarboxylic acid such as p-aminomethylbenzoic acid as a copolymerized unit. The ratio of these copolymer units in the m-xylylene group-containing polyamide is preferably 20 mol% or less, and more preferably 15 mol% or less.

The m-xylylene group-containing polyamide is preferably produced by a melt polycondensation method (melt polymerization method). For example, the following methods are used: a nylon salt comprising a diamine and a dicarboxylic acid is polymerized in a molten state in the presence of water while heating under pressure and removing added water and polycondensation water. Alternatively, the diamine may be produced by a method in which the diamine is directly added to a dicarboxylic acid in a molten state to perform polycondensation. In this case, the diamine is continuously added to the dicarboxylic acid in order to keep the reaction system in a uniform liquid state, and during this time, the polycondensation is allowed to proceed while the reaction system is heated in order to keep the reaction temperature at not lower than the melting points of the amide oligomer and the polyamide to be formed.

In order to obtain the effect of promoting the amidation reaction and the effect of preventing coloration during the polycondensation, a phosphorus atom-containing compound may be added to the polycondensation system of the m-xylylene group-containing polyamide.

Examples of the compound containing a phosphorus atom include: dimethylphosphinic acid, phenylmethylphosphinic acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, calcium hypophosphite, ethyl hypophosphite, phenylphosphonous acid, sodium phenylphosphinate, potassium phenylphosphinate, lithium phenylphosphinate, ethyl phenylphosphinate, phenylphosphonic acid, ethylphosphonic acid, sodium phenylphosphonate, potassium phenylphosphinate, lithium phenylphosphinate, diethyl phenylphosphonate, sodium ethylphosphonate, potassium ethylphosphonate, phosphorous acid, sodium hydrogen phosphite, sodium phosphite, triethyl phosphite, triphenyl phosphite, pyrophosphorous acid, and the like. Among them, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, calcium hypophosphite, and other metal hypophosphite are preferably used because they have a high effect of promoting the amidation reaction and also have an excellent effect of preventing coloration, and sodium hypophosphite is particularly preferable. The compounds containing a phosphorus atom which can be used in the present invention are not limited to these compounds.

The amount of the compound containing a phosphorus atom added to the polycondensation system of the m-xylylene group-containing polyamide is preferably 1to 500ppm, more preferably 5 to 450ppm, and still more preferably 10 to 400ppm in terms of the phosphorus atom concentration in the m-xylylene group-containing polyamide, from the viewpoint of preventing coloration of the m-xylylene group-containing polyamide during the polycondensation.

It is preferable that: an alkali metal compound or an alkaline earth metal compound is added to a polycondensation system of a polyamide containing an m-xylylene group in combination with a compound containing a phosphorus atom. The presence of a sufficient amount of a phosphorus atom-containing compound is necessary for preventing coloration of the m-xylylene group-containing polyamide in the polycondensation, but in order to adjust the amidation reaction rate, it is preferable to co-exist an alkali metal compound or an alkaline earth metal compound.

Examples thereof include: and alkali metal/alkaline earth metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide, and barium hydroxide, and alkali metal/alkaline earth metal acetates such as lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, magnesium acetate, calcium acetate, and barium acetate. Among them, sodium acetate is particularly preferable. The alkali metal compound or alkaline earth metal compound that can be used in the present invention is not limited to these compounds.

When an alkali metal compound or an alkaline earth metal compound is added to a polycondensation system of a m-xylylene group-containing polyamide, the value obtained by dividing the number of moles of the compound by the number of moles of a phosphorus atom-containing compound is preferably 0.5 to 2.0, more preferably 0.6 to 1.8, and still more preferably 0.7 to 1.5. By setting the amount of the alkali metal compound or the alkaline earth metal compound to the above range, the amidation reaction promoting effect of the phosphorus atom-containing compound can be obtained and the formation of gel can be suppressed.

The m-xylylene group-containing polyamide obtained by melt polycondensation was taken out at once and pelletized. The obtained pellets may be dried or subjected to solid-phase polymerization for further increasing the degree of polymerization. As the heating apparatus used for drying or solid-phase polymerization, a continuous heating and drying apparatus; a rotary drum type heating device called a drum dryer, a conical dryer, a rotary dryer, or the like, and a conical type heating device called a conical mixer having a rotating blade therein are used. In particular, in the case of solid-phase polymerization of polyamide, a rotary drum type heating apparatus among the above apparatuses is preferably used in view of being able to seal the system and facilitating polycondensation in a state where oxygen which causes coloring is removed.

The moisture content of the m-xylylene group-containing polyamide used in the present invention is preferably 0.001 to 0.5% by mass, more preferably 0.005 to 0.4% by mass, and still more preferably 0.01 to 0.3% by mass. By setting the moisture content of the m-xylylene group-containing polyamide to 0.5% by mass or less, it is possible to prevent moisture from vaporizing and generating bubbles in the molded article during molding. On the other hand, as the moisture content becomes lower, the viscosity in a softened state becomes higher, and the lamellar dispersion state is easily maintained, and by setting the moisture content to 0.001 mass% or more, the drying time in the production of the m-xylylene group-containing polyamide can be shortened, and coloring and thermal deterioration can be prevented.

((B) aliphatic Polyamide)

The aliphatic polyamide used in the present invention contains 75 to 95 mol% of aminocaproic acid units and 25 to 5 mol% of hexamethylene adipamide units, based on the total structural units of the aliphatic polyamide. The aliphatic polyamide used in the present invention is a nylon 6/nylon 66 copolymer, so-called "nylon 6/66".

The aliphatic polyamide has a content of the-aminocaproic acid unit of 75 to 95 mol%, preferably 80 to 90 mol%, based on the total structural units of the aliphatic polyamide. When the content of the aminocaproic acid unit is less than 75 mol%, a proper barrier property cannot be obtained, and when it exceeds 95 mol%, the crystallization rate becomes too high, which affects moldability.

Compounds which may constitute aminocaproic acid units are caprolactam and 6-aminocaproic acid.

The aliphatic polyamide contains 25 to 5 mol%, preferably 20 to 10 mol% of hexamethylene adipamide units based on the total structural units of the aliphatic polyamide. When the content of the hexamethylene adipamide unit exceeds 25 mol%, appropriate toughness cannot be obtained, and when the content is less than 5 mol%, the crystallization rate is too high, which affects moldability.

Compounds which may constitute hexamethylene adipamide units are adipic acid and hexamethylenediamine.

The aliphatic polyamide used in the present invention can be produced by copolycondensating caprolactam and/or 6-aminocaproic acid, adipic acid and hexamethylenediamine.

(melting Point of Polyamide)

The melting point (Tm (a)) of the M-xylylene group-containing polyamide (a) before dry blending, the melting point (Tm (B)) of the aliphatic polyamide (B) before dry blending, and the melting point peak (Tm (a, M)) of the M-xylylene group-containing polyamide (a) and the melting point peak (Tm (B, M)) of the aliphatic polyamide (B) in the molded article of the dry blended mixture were measured by differential scanning calorimetry. Specifically, the measurement can be carried out by the method described in the examples below. The "molded article of the dry-blended mixture" in the present invention refers to a molded article obtained by melt-mixing (a) a dry-blended mixture containing m-xylylene and (B) an aliphatic polyamide in an extruder or the like and molding the mixture.

Further, Tm (A) and Tm (A, M) preferably satisfy the following relationship (1). That is, the melting point (tm) (a)) of the m-xylylene group-containing polyamide (a) is preferably: when a molded article of the dry-blended mixture is produced, the melting point is lowered to within 3.0 ℃, more preferably within 1.5 ℃, and still more preferably within 1.0 ℃ from the melting point before dry blending.

Tm(A)-3≤Tm(A，M)≤Tm(A)(1)

When the melting point (Tm (a)) of the M-xylylene group-containing polyamide (a) before dry blending and the melting point (Tm (a, M)) of the M-xylylene group-containing polyamide in the molded article of the dry blended mixture satisfy formula (1), the compatibility of the M-xylylene group-containing polyamide (a) and the aliphatic polyamide (B) constituting the molded article can be suppressed, and therefore, the superiority of each polyamide is remarkably exhibited, and the molded article is excellent in gas barrier properties and flexibility.

The melting point (Tm (A)) of the m-xylylene group-containing polyamide (A) before dry-blending is preferably 227 to 238 ℃, more preferably 228 to 237.5 ℃.

The melting point peak (Tm (A, M)) of the M-xylylene group-containing polyamide (A) in the molded article of the dry-blended mixture is preferably 225 to 237.5 ℃ and more preferably 225.5 to 237 ℃.

Further, Tm (B) and Tm (B, M) preferably satisfy the following relationship (2). That is, the melting point (tm (B)) of the aliphatic polyamide (B) is preferably within 3 ℃, more preferably within 2.7 ℃, and even more preferably within 2.5 ℃ from the melting point before dry blending when a molded article of a dry blended mixture is produced.

Tm(B)-3≤Tm(B，M)≤Tm(B)(2)

When the melting point (Tm (B)) of the aliphatic polyamide (B) before dry blending and the melting point (Tm (B, M)) of the aliphatic polyamide in the molded article obtained by dry blending the mixture satisfy formula (2), the aliphatic polyamide (B) and the M-xylylene group-containing polyamide (a) constituting the molded article are prevented from being compatible with each other, and the aliphatic polyamide (B) is dispersed in the M-xylylene group-containing polyamide (a) in columnar form, whereby the molded article having excellent gas barrier properties is obtained.

The melting point (Tm (B)) of the aliphatic polyamide (B) before dry blending is preferably 196 to 200 ℃ and more preferably 197 to 200 ℃ as measured by differential scanning calorimetry.

The melting point peak (Tm (B, M)) of the aliphatic polyamide (B) in the molded article of the dry-blended mixture is preferably in the range of 195 to 199 ℃ and more preferably 196 to 199 ℃.

The heat of fusion of the polyamide (A) in the molded article of the dry-blended mixture is preferably in the range of-70 to-30J/g, more preferably-60 to-31J/g, from the viewpoint of preferably having appropriate crystallinity.

The heat of fusion of the polyamide (B) in the molded article of the dry-blended mixture is preferably in the range of-55 to-7J/g, more preferably-50 to-8J/g, from the viewpoint of preferably having appropriate crystallinity.

(relative viscosity of Polyamide)

There are several indicators of the degree of polymerization of polyamides, and the relative viscosity is generally used. The relative viscosity of the m-xylylene group-containing polyamide (a) used in the present invention is preferably 1.5 to 4.5, more preferably 2.0 to 4.2, and still more preferably 2.5 to 4.0, from the viewpoint of gas barrier properties. From the viewpoint of moldability, the relative viscosity of the aliphatic polyamide (B) used in the present invention is preferably 2.5 to 5.0, more preferably 2.8 to 4.8, and still more preferably 3.0 to 4.5. From the viewpoints of moldability, controllability of a microphase-separated structure, and compatibility, the difference between the relative viscosity of (A) the m-xylylene group-containing polyamide and the relative viscosity of (B) the aliphatic polyamide is preferably in the range of 0.6 to 1.6, more preferably 0.7 to 1.5.

Here, the relative viscosity is: 0.2g of polyamide was dissolved in 20mL of 96 mass% sulfuric acid, and the falling time (t) measured at 25 ℃ with a Cannon-Fenske viscometer and the falling time (t) of 96 mass% sulfuric acid itself measured in the same manner₀) The ratio of (d) is represented by the following formula.

Relative viscosity t/t₀

(mass ratio of (A) m-xylylene group-containing polyamide to (B) aliphatic polyamide)

In the dry-blended mixture of the present invention, the mass ratio ((A)/(B)) of the (A) m-xylylene group-containing polyamide to the (B) aliphatic polyamide is in the range of 55/45 to 65/35, preferably 57/43 to 63/37. When the total of the m-xylylene group-containing polyamide (a) and the aliphatic polyamide (B) in the dry-blended mixture of the present invention is 100 mass%, the m-xylylene group-containing polyamide content is less than 55 mass%, the gas barrier properties are insufficient, and when it exceeds 65 mass%, the flexibility is insufficient, and the tensile elongation at break is reduced when the mixture is formed into a molded article such as a film. On the other hand, if the content of the aliphatic polyamide exceeds 45 mol%, the gas barrier properties are insufficient, and if it is less than 35 mol%, the flexibility is insufficient.

(Dry blending)

The dry-blended mixture of the present invention can be obtained by dry-blending (a) the m-xylylene group-containing polyamide and (B) the aliphatic polyamide, and specifically, can be obtained by a method comprising the steps of: the particles of the m-xylylene group-containing polyamide (A) and the particles of the aliphatic polyamide (B) are dry-blended so that the mass ratio ((A)/(B)) of the m-xylylene group-containing polyamide (A) to the aliphatic polyamide (B) is in the range of 55/45 to 65/35.

When a molded article is produced by using resin composition pellets obtained by previously melt-mixing (a) a metaxylylene group-containing polyamide and (B) an aliphatic polyamide and further melt-mixing the resin composition pellets by an extruder or the like, the gas barrier property is not sufficient. On the other hand, when a molded article is produced by using the dry-blended mixture of the present invention obtained by dry-blending (a) a polyamide containing m-xylylene and (B) an aliphatic polyamide and melt-blending the mixture by an extruder or the like, a molded article having excellent gas barrier properties, transparency and toughness can be obtained.

When a molded article is produced by melt-mixing in an extruder, it is not preferable that the extrusion temperature is excessively increased and the retention time is excessively long, because the (a) m-xylylene group-containing polyamide and the (B) aliphatic polyamide are compatible with each other, and the gas barrier property of the obtained molded article is lowered. The molding temperature is preferably 245 to 270 ℃, more preferably 250 to 265 ℃. The residence time varies depending on the size of the extruder and the like, and therefore cannot be summarized, and is preferably 10 minutes or less, more preferably 5 minutes or less.

When the resin composition pellets are produced by melt-mixing the m-xylylene group-containing polyamide (a) and the aliphatic polyamide (B) in advance to produce the resin composition pellets and then melt-mixing the resin composition pellets to produce the molded article, the m-xylylene group-containing polyamide (a) and the aliphatic polyamide (B) are melt-mixed at the stage of producing the resin composition pellets and are made compatible by the amide exchange reaction. Further, when a molded article such as a film is produced using the resin composition pellet, the amide exchange reaction is further advanced to further cause the compatibility, and thus the gas barrier property of the m-xylylene group-containing polyamide (a) cannot be sufficiently exhibited. In contrast, in the dry-blended mixture of the present invention, since the (a) m-xylylene group-containing polyamide and the (B) aliphatic polyamide are present as respective polyamides in a state of the mixture and are first melt-mixed at the time of producing a molded article by melt-mixing the dry-blended mixture by an extruder or the like, the (a) m-xylylene group-containing polyamide and the (B) aliphatic polyamide can be maintained in a phase-separated state although the transamidation reaction slightly proceeds, and the gas barrier properties possessed by the (a) m-xylylene group-containing polyamide can be exhibited.

(compatibility inhibitor)

The dry mix of the present invention may further comprise a compatibility inhibitor. The dry-blended mixture of the present invention can suppress the compatibility of (a) the m-xylylene group-containing polyamide and (B) the aliphatic polyamide during molding processing using the mixture even if the mixture does not contain a compatibility inhibitor, and can suppress the compatibility more reliably by containing the compatibility inhibitor, and can provide a stable molded article excellent in gas barrier properties, transparency and toughness.

As the compatibility inhibitor, there can be used: hydroxides of alkali metals or alkaline earth metals, carboxylates of alkali metals or alkaline earth metals. The alkali metal or alkaline earth metal carboxylate is preferably an alkali metal or alkaline earth metal carboxylate having 1to 6 carbon atoms, more preferably an alkali metal or alkaline earth metal carboxylate having 1to 3 carbon atoms, and still more preferably an alkali metal or alkaline earth metal acetate. Preferable specific examples of the compatibility inhibitor include: sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium acetate, potassium acetate, calcium acetate, and the like, and more preferably at least 1 selected from the group consisting of sodium acetate and calcium hydroxide.

The content of the compatibilization inhibitor in the dry-blended mixture of the present invention is preferably 300 to 4000 mass ppm, more preferably 500 to 3000 mass ppm, relative to 100 parts by mass of the total amount of the (A) m-xylylene group-containing polyamide and the (B) aliphatic polyamide.

(method for preparing Dry-mix mixture)

The method for producing a dry-blended mixture of the present invention comprises the steps of: the particles of the m-xylylene group-containing polyamide (A) and the particles of the aliphatic polyamide (B) are dry-blended so that the mass ratio ((A)/(B)) of the m-xylylene group-containing polyamide (A) to the aliphatic polyamide (B) is in the range of 55/45-65/35. When the compatibilizing agent is added, when the (A) m-xylylene group-containing polyamide and the (B) aliphatic polyamide are dry-blended, the compatibilizing agent is preferably added in an amount of 300 to 4000 ppm by mass based on 100 parts by mass of the total amount of the (A) m-xylylene group-containing polyamide and the (B) aliphatic polyamide.

The dry-blended mixture of the present invention can be prepared by mixing (a) the m-xylylene group-containing polyamide and (B) the aliphatic polyamide, and further, if necessary, the compatibilizing agent, using a known mixing device such as a drum mixer or a cone mixer. The mixing device is preferably a closed type structure that can be purged with an inert gas such as nitrogen and is less likely to allow oxygen and moisture to enter from the outside.

(additives and spreading Agents)

From the viewpoint of suppressing the generation of a gelled product when molding is performed using the dry-blended mixture of the present invention and from the viewpoint of improving extrusion processability, the mixture preferably contains ethylene bis (stearamide) or calcium stearate. The content of these compounds in the dry-blended mixture is preferably 100 to 4000 mass ppm, more preferably 200 to 3000 mass ppm, and further preferably 300 to 2000 mass ppm. The ethylene bis (stearamide) or calcium stearate is preferably vegetable-based.

Ethylene bis (stearamide) or calcium stearate is preferably spread onto the surface of the dry mix mixture by means of a non-ionic surfactant.

The average particle diameter of the ethylene bis (stearamide) or calcium stearate is preferably 0.01 to 3.0mm, more preferably 0.02 to 1.0mm, from the viewpoint of uniformly spreading on the surface of the dry-blended mixture.

Specific examples of the nonionic surfactant include: fatty acid monoglyceride, fatty acid diglyceride, fatty acid triglyceride, fatty acid alkyl ester, alkyl alcohol, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkyldiethanolamine, hydroxyalkylmonoethanolamine, polyoxyethylene alkylamine fatty acid ester, polyoxyethylene glyceride of isoalkylcarboxylic acid, polyoxyethylene glyceride of triisoalkylcarboxylic acid, polyoxyethylene trimethylolpropane monoalkylcarboxylate, polyoxyethylene trimethylolpropane dialkylcarboxylate, monoethanolamide fatty acid, diethanolamide fatty acid monoisopropanolamide fatty acid ester, polyoxyethylene fatty acid amide, polyoxyethylene sorbitan monoalkylcarboxylate, polyoxyethylene sorbitan alkylcarboxylate, sorbitan monoalkylcarboxylate, sorbitan sesquialkylcarboxylate, sorbitan dialkylcarboxylate, alkyl alkylester fatty acid ester, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monoalkylcarboxylate, polyoxyethylene sorbitan dialkylester, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan fatty acid ester, sorbitan esters of trialkyl carboxylic acids, sorbitan esters of tetraalkyl carboxylic acids, polyethylene glycol esters of mono-fatty acids, polyethylene glycol esters of di-fatty acids, polyoxyethylene sorbitol esters of alkyl carboxylic acids, sucrose fatty acid esters, and the like. The nonionic surfactant is not particularly limited, and is preferably an alkyl carboxylic acid polyoxyethylene sorbitan ester, and more preferably polyoxyethylene sorbitan monolaurate.

The content of the nonionic surfactant in the dry-blended mixture is preferably 30 to 800 mass ppm, more preferably 50 to 600 mass ppm, and still more preferably 80 to 400 mass ppm.

In the method for producing a dry-blended mixture in which ethylene bis (stearamide) or calcium stearate is spread over the surface of the dry-blended mixture, it is preferable that the step of dry-blending (a) the m-xylylene group-containing polyamide and (B) the aliphatic polyamide is followed by the following steps: 30 to 800 ppm by mass of a nonionic surfactant is added to 100 parts by mass of the total amount of (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide, and then 100 to 4000 ppm by mass of ethylene bis (stearamide) or calcium stearate is added to 100 parts by mass of the total amount of (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide.

(molded body)

Various molded articles can be obtained by melt-mixing the dry-blended mixture of the present invention and molding the mixture. Examples of the molded article include: films, sheets, injection molded bottles, blow molded bottles, injection molded cups, and the like, with films and sheets being preferred. The films and sheets preferably comprise a layer formed from the dry blended mixture of the present invention.

The layer structure in the film or sheet is not particularly limited, and the number and type of layers are not particularly limited. The film and sheet may be a single layer of the "layer (a)" formed only of the dry-blended mixture of the present invention, and may also be a multilayer having the layer (a) and other layers. When the layer formed from the dry-blended mixture of the present invention is the "layer (a)" and the layer formed from the other resin is the "layer (B)" as the constitution of the plurality of layers, the structure may be an a/B structure including 1 layer of the (a) and 1 layer of the (B), a 3-layer structure including B/a/B of 1 layer of the (a) and 2 layers of the (B), or a 3-layer structure including a/B/a of 2 layers of the (a) and 1 layer of the (B). Further, a 5-layer structure of B1/B2/a/B2/B1 including 24 layers of layer (B) of 1 layer (a) and layer (B1) and layer (B2) may be employed. The multilayer film and the multilayer sheet may further contain an optional layer such as an adhesive layer (AD) if necessary, and may have, for example, a 5-layer structure of B/AD/a/AD/B or a 5-layer structure of a/AD/B.

As the resin constituting the layer made of a resin other than the dry-blended mixture of the present invention, any resin can be used, and there is no particular limitation. For example, thermoplastic resins can be used, and specific examples thereof include: polyolefins (e.g., polyethylene, polypropylene), polyesters (e.g., polyethylene terephthalate (PET), polybutylene terephthalate (PBT)), polyamides (not comprising the dry blended mixture of the present invention; e.g., nylon 6, nylon 66, nylon 6/66, m-xylylene adipamide (MXD6)), ethylene-vinyl alcohol copolymers (EVOH), and plant-derived resins (e.g., polylactic acid, polyglycolic acid), preferably comprising at least one selected from the group consisting of these resins.

Examples of the optional layer that can be contained in the multilayer film or multilayer sheet include: adhesive layers, metal foils, metal vapor deposited layers, and the like.

The adhesive layer preferably contains a thermoplastic resin having adhesiveness. Examples of the thermoplastic resin having adhesiveness include: an acid-modified polyolefin resin obtained by modifying a polyolefin resin such as polyethylene or polypropylene with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, or itaconic acid. The adhesive layer is preferably modified from the viewpoint of adhesiveness with the same kind of resin as the resin constituting the layer made of a resin other than the dry blend mixture of the present invention. The thickness of the adhesive layer is preferably 2 to 100 μm, more preferably 5 to 90 μm, and still more preferably 10 to 80 μm, from the viewpoint of securing practical adhesive strength and molding processability.

As the metal foil, aluminum foil is preferable. The thickness of the metal foil is preferably 3 to 50 μm, more preferably 3 to 30 μm, and still more preferably 5 to 15 μm from the viewpoint of gas barrier properties, light-shielding properties, bending resistance, and the like.

As the metal vapor deposition layer, a resin film or the like deposited with a metal such as aluminum or aluminum oxide or a metal oxide film can be used. The method for forming the vapor deposition film is not particularly limited, and examples thereof include: physical vapor deposition methods such as vacuum vapor deposition, sputtering, and ion plating; chemical vapor deposition methods such as PECVD. The thickness of the vapor deposition film is preferably 5 to 500nm, more preferably 5 to 200nm, from the viewpoint of gas barrier properties, light-shielding properties, bending resistance, and the like.

The method for producing the molded article is not particularly limited, and the molded article can be produced by any method, for example, extrusion molding or injection molding. Further, a molded article obtained by extrusion molding or injection molding may be further subjected to molding processing by uniaxial stretching, biaxial stretching, stretch blow molding, or the like. In addition, from the viewpoint of reliably suppressing the compatibility of the (a) m-xylylene group-containing polyamide and the (B) aliphatic polyamide when molding using the dry-blended mixture of the present invention, the dry-blended mixture of the present invention and the compatibility inhibitor may be fed into an extruder, and the dry-blended mixture of the present invention and the compatibility inhibitor may be melt-mixed in the extruder.

Specifically, the film or sheet can be processed by an extrusion method or a blown film method having a T-die, and the obtained material can be subjected to a stretching process to obtain a stretched film or a heat-shrinkable film. Examples of the stretching method include: the extruded film is continuously subjected to sequential biaxial stretching by a tenter system, simultaneous biaxial stretching, and simultaneous biaxial stretching by an inflation system. In addition, a batch biaxial stretching apparatus may be used. The extrusion stretch ratio may be determined as appropriate depending on the use of the film, and it is preferable to perform biaxial stretching by stretching 1.1 to 15 times in the MD and 1.1 to 15 times in the TD.

Further, the injection molded cup may be formed by injection molding and the blow molded bottle may be formed by blow molding, or the bottle may be formed by injection molding after the preform is formed by injection molding and further blow molding.

Further, a multilayer film having at least 1 layer formed of the dry blended mixture of the present invention can also be produced by a method such as extrusion lamination, coextrusion or the like, for example, by combining other resins such as polyethylene, polypropylene, nylon 6, PET, metal foil, paper or the like.

The processed film and sheet can be used for packaging containers such as preservative films, bags with various shapes, cover materials of containers, bottles, cups, trays, pipes and the like. Further, a preform or a bottle having a multilayer structure with PET or the like may be processed by multilayer injection molding or the like.

Film-coated containers may also be made by applying a film comprising a layer formed from the dry-blended mixture of the present invention to all or a portion of the container. The form of the film packaging container is not particularly limited, and may be selected from a suitable range according to the article to be stored or preserved, and specific examples thereof include: three-side sealed flat bags, self-standing bags, gusset packaging bags, pillow-shaped packaging bags, shrink film packaging and the like.

From the viewpoint of gas barrier properties, transparency and toughness, the molded article of the dry-blended mixture of the present invention preferably has a microphase separation structure, particularly preferably a columnar structure, in which the (a) m-xylylene group-containing polyamide and the (B) aliphatic polyamide are incompatible with each other. The columnar structure provides a molded article having a pseudo-layered structure, and thus the gas barrier properties are excellent. This effect is particularly remarkable in stretched molded articles such as stretched films and blow molded bottles.

The columnar crystalline domains of the columnar structure are preferably (B) the aliphatic polyamide from the viewpoint of gas barrier properties, transparency, and toughness. From the viewpoint of forming a pseudo-layer structure, the diameter of the columnar domains is preferably 100 to 200nm, more preferably 120 to 180 nm. From the same viewpoint, the MD length of the columnar domain is preferably 200nm to 3 μm, more preferably 250nm to 1 μm, and the MD length is preferably longer than the TD length.

Whether or not the columnar structure is present in the molded article of the present invention can be confirmed by the method described in examples.

The molded article obtained by using the dry-blended mixture of the present invention is excellent in gas barrier properties, transparency and toughness. These molded articles can be used as packaging materials, packaging containers, and fiber materials.

The film packaging container using the dry mix of the present invention is excellent in gas barrier properties and transparency, and therefore is suitable for packaging various articles.

Examples of the object to be preserved include: milk, dairy products, fruit juice, coffee, tea, alcoholic beverages, etc.; sauce, salad flavoring, soup, Japanese dish, curry, infant food, and nursing food; pasty food such as jam and mayonnaise; aquatic products such as tuna and seafood; milk processed products such as cheese and butter; processed livestock meat such as meat, sausage, ham, etc.; vegetables such as carrot and potato; eggs; flour; processed rice products such as pre-cooked rice, rice porridge, etc.; dried foods such as powdered flavoring agent, powdered coffee, powdered milk powder for infants, powdered diet food, dried vegetables, rice cake, etc.; chemicals such as pesticides, insecticides, etc.; a pharmaceutical; a cosmetic; a pet food; miscellaneous goods such as shampoo, hair conditioner, lotion, etc.; various articles are provided.

After filling the objects, the film packaging container or the objects may be sterilized so as to be suitable for the objects. Examples of the sterilization method include: heat sterilization such as hot water treatment at 100 deg.C or lower, pressurized hot water treatment at 100 deg.C or higher, and ultrahigh-temperature heat treatment at 130 deg.C or higher; electromagnetic wave sterilization by ultraviolet rays, microwaves, gamma rays, or the like; gas treatment of ethylene oxide and the like; and sterilizing agents such as hydrogen peroxide and hypochlorous acid.

Examples

The present invention will be described in more detail with reference to examples. Various evaluations in examples and the like were performed by the following methods.

(1) Relative viscosity

0.2g of a sample was precisely weighed, and the sample was stirred at 20 to 30 ℃ into 20mL of 96 mass% sulfuric acid to be completely dissolved. After complete dissolution, 5mL of the solution was quickly taken out to a Cannon-Fenske viscometer and left to stand at a constant temperature of 25 ℃ for 10 minutes, and then the drop time (t) was measured. In addition, the falling time (t) of 96 mass% sulfuric acid itself was measured in the same manner₀). Based on t and t0, the relative viscosity was calculated using the following formula.

Relative viscosity t/t₀

(2) Melting point and heat of fusion

The melting point and the heat of fusion were determined by DSC measurement (differential scanning calorimetry) at a temperature increase rate of 10 ℃ per minute under a nitrogen gas stream using a differential scanning calorimeter "DSC-60" (manufactured by Shimadzu corporation).

(3) Tensile Strength test

The films obtained in examples and comparative examples were subjected to humidity adjustment for 1 week at 23 ℃ under an atmosphere of 50% RH (relative humidity) using a tensile tester "ストログラフ V1-C" (manufactured by Toyo Seiki Seisaku-sho Co., Ltd.) and then the tensile elastic modulus, tensile strength at break and tensile elongation at break were measured in accordance with ASTM D882.

(4) HAZE (HAZE) and Yellowness Index (YI)

The film obtained in the examples or comparative examples was subjected to humidity adjustment for 1 week at 23 ℃ under an atmosphere of 50% RH (relative humidity) according to JIS K7105 using a HAZE value measuring apparatus "COH-400A" (manufactured by Nippon Denshoku industries Co., Ltd.), and then HAZE and YI were measured.

(5) Oxygen Transmission Rate (OTR) (oxygen Barrier Property of Single-layer film and Multi-layer film)

The oxygen permeability was measured using an oxygen permeability measuring apparatus "OXTRAN 2/21 SH" (manufactured by Mocon corporation) according to ASTM D3985 under an atmosphere of 23 ℃ and 60% RH (relative humidity) until the oxygen permeability value was stable.

(6) Oxygen Transmission Rate (OTR) after retort treatment (oxygen barrier Property of multilayer film)

The multilayer film was subjected to a retort treatment at 121 ℃ for 30 minutes using an autoclave "SR-240" (Tomy Seiko Co., Ltd., manufactured by Ltd.), and then the oxygen permeability was measured for 180 days under an atmosphere of 23 ℃ and 60% RH (relative humidity) or 23 ℃ and 80% RH (relative humidity) according to ASTM D3985 using an oxygen permeability measuring apparatus "OXTRAN 2/61" (manufactured by Mocon Co., Ltd.). The cumulative oxygen permeabilities for 30 days and 180 days were calculated based on the results.

(7) Domain size determination by morphological observation

After the multilayer film sample was cut into 1cm × 3cm, the surface and back of the film sample were coated with epoxy resin and cured at room temperature for 24 hours. Ultrathin sections of 100nm thickness were made from the MD and TD sections of the cured samples, respectively. After the ultrathin section was stained with ruthenium tetroxide, the ultrathin section was morphologically observed under the following conditions using an ultra-High resolution field emission type scanning electron microscope "FE-SEM SU-8020" (manufactured by High-Technologies Corporation), and the average domain size was determined based on the observed image.

The average diameter (TD direction) of the columnar domains and the length in the MD direction were observed in a range of 100 μm × 20 μm with respect to the gas barrier layer of the multilayer thin film by using an FE-SEM, and the length in the MD direction and the length in the TD direction of each domain were measured for a plurality of domains existing in the region, and the average value thereof was used. As a representative example, SEM photographs of morphological observation of the gas barrier layer of the multilayer thin film obtained in example 5 are shown in fig. 1 and 2. Fig. 1 is a photograph for measuring the MD-direction length of the columnar crystal domains, and fig. 2 is a photograph for measuring the average diameter (TD-direction) of the columnar crystal domains. The black portions observed in fig. 1 and 2 are columnar domains derived from the aliphatic polyamide (B1).

(SEM Observation conditions)

Acceleration voltage: 30kV

Observation magnification: 5 ten thousand times

Working distance: 8mm

A detector: TE

Inclination: is free of

Probe current: 20 mu A, Normal

A condenser lens: 5

Conducting treatment: w vapor deposition (3 minutes)

(8) Impact strength

The multilayer stretched film obtained in example 13 was subjected to humidity control in an atmosphere of 50% RH (relative humidity) at 23 ℃, and then subjected to a film impact tester "ITF-60" (manufactured by eastern precision industries co., ltd.) using a tip: 1/2-inch spherical, 30kg cm weight.

(9) Shrinkage rate during storage

A square of 10 cm. times.10 cm was drawn at the center of the multilayer stretched film obtained in example 13, and the film was allowed to stand at 40 ℃ and 50% RH in a constant temperature and humidity chamber for 3 hours, and then the area of the square was measured to determine the shrinkage based on the area before and after the heat treatment.

The biaxially stretched film obtained in example 13 was also allowed to stand at 40 ℃ and 50% RH for 48 hours, and then the shrinkage was measured.

(10) Shrinkage after boiling

A square of 10cm × 10cm was drawn at the center of the multilayer stretched film obtained in example 13, and then boiled at 90 ℃ for 30 minutes using an autoclave "SR-240" (Tomy Seiko co., ltd.). After the boiling treatment, the humidity was adjusted for 1 week in an atmosphere of 23 ℃ and 50% RH (relative humidity), and then the area of the square was measured to determine the shrinkage based on the area before and after the heat treatment.

(11) Maximum shrinkage

A square of 10 cm. times.10 cm was drawn at the center of the multilayer stretched film obtained in example 13, and then the film was put into a hot air dryer and heat-treated at 120 ℃ for 30 seconds. The area of the square after the heat treatment was measured, and the shrinkage rate was determined based on the area before and after the heat treatment.

Production example 1

(production of m-xylylene group-containing Polyamide (A1))

13000g (88.95mol) of Adipic Acid (AA), 0.3749g (0.0035mol) of sodium hypophosphite and 0.1944g (0.0024mol) of sodium acetate were weighed accurately and charged into a pressure-resistant reaction vessel having an internal volume of 50L and equipped with a stirrer, a partial condenser, a total condenser, a pressure regulator, a thermometer, a dropping tank, a pump, a liquid aspirator, a nitrogen introduction pipe, a bottom discharge valve and a strand die, and after sufficient replacement of nitrogen gas, the reaction vessel was closed and the temperature of the reaction vessel was raised to 170 ℃ while maintaining the internal pressure of the reaction vessel at 0.4MPaG with stirring.

After the temperature reached 170 ℃, 12042g (88.42mol) of m-xylylenediamine (MXDA) stored in the dropping vessel was added dropwise to the molten raw material in the reaction vessel, and the temperature in the reaction vessel was continuously raised to 260 ℃ while discharging the generated condensed water to the outside of the system while maintaining the pressure in the reaction vessel at 0.4 MPaG.

After the completion of the dropwise addition of m-xylylenediamine, the inside of the reaction vessel was slowly returned to normal pressure, and then the inside of the reaction vessel was depressurized to 80kPaG by using a liquid aspirator to remove the condensation water. The stirring torque of the stirrer was observed when the pressure was reduced, and at the time point when the stirring torque reached a predetermined torque, the inside of the reaction vessel was pressurized with nitrogen, the bottom discharge valve was opened, and the polymer was discharged from the strand die to form strands, which were then cooled and pelletized by a pelletizer.

Subsequently, the pellets were put into a stainless steel rotary drum type heating apparatus and rotated at 5 rpm. Then, the inside of the reaction system was heated from room temperature (23 ℃) to 150 ℃ under a small nitrogen gas flow while sufficiently substituting nitrogen gas. The pressure was reduced to 1torr or less at the time point when the temperature in the reaction system reached 150 ℃ and the temperature in the reaction system was further raised to 190 ℃ over 110 minutes. The solid-phase polymerization was continued at the same temperature for 120 minutes from the time point when the temperature in the reaction system reached 180 ℃. After completion of the reaction, the pressure was reduced, the temperature in the reaction system was lowered under a nitrogen stream, and pellets were taken out at a time point at which 60 ℃ was reached, whereby m-xylylene group-containing polyamide (a1) (relative viscosity 2.65, melting point 237.0 ℃) as an MXDA/AA copolymer (MXDA: AA: 49.85: 50.15 (mol%)) was obtained.

Production example 2

(production of m-xylylene group-containing Polyamide (A2))

A metaxylylene group-containing polyamide (A2) (relative viscosity: 3.2, melting point: 237.0 ℃) was obtained as an MXDA/AA copolymer (MXDA: AA: 49.85: 50.15 (mol%)), except that the solid-phase polymerization time was changed to 180 minutes from the time point at which the temperature in the reaction system reached 180 ℃.

Production example 3

(production of m-xylylene group-containing Polyamide (A3))

A pressure-resistant melt polymerization reactor having an internal volume of 50L and equipped with a stirrer, a partial condenser, a total condenser, a pressure regulator, a thermometer, a dropping tank, a pump, a liquid aspirator, a nitrogen inlet tube, a bottom discharge valve, and a strand die was charged with accurately weighed 12120g (82.94mol) of adipic acid, 880g (5.29mol) of isophthalic acid (IPA), 10.96g (0.10mol) of sodium hypophosphite, and 5.68g (0.07mol) of sodium acetate, and the melt polymerization reactor was sufficiently purged with nitrogen, and then the melt polymerization reactor was closed, and the temperature of the melt polymerization reactor was raised to 170 ℃ while maintaining 0.4MPaG in the melt polymerization reactor under stirring.

After reaching 170 ℃, 11520g (84.59mol) of m-xylylenediamine (a diamine component/dicarboxylic acid component molar ratio (MXDA/(AA + IPA)) -0.9587) stored in a dropping tank was added dropwise to the molten raw material in the melt polymerization reactor, and the temperature in the melt polymerization reactor was continuously raised to 260 ℃ while discharging the generated condensed water to the outside of the system while maintaining the pressure in the melt polymerization reactor at 0.4 MPaG.

After the completion of the dropwise addition of m-xylylenediamine, the inside of the melt polymerization vessel was slowly returned to normal pressure, and then the inside of the melt polymerization vessel was depressurized to 80kPaG by using a liquid aspirator to remove the polycondensation water. The stirring torque of the stirrer was observed under reduced pressure, and at the time point when the stirring torque reached a predetermined torque, the inside of the melt polymerization vessel was pressurized with nitrogen, and the bottom drain valve was opened to obtain an isophthaloyl group-containing polyamide (a3) (isophthalic acid content: 6 mol%) (relative viscosity: 2.65, melting point: 229.0 ℃).

Production example 4

(production of aliphatic Polyamide (B2))

In the reaction vessel used in production example 1, a reaction mixture of caprolactam: hexamethylene-adipate 70: the aliphatic polyamide (B1) and the aliphatic polyamide (B3) described later were adjusted to 30 (mol%), and after sufficient nitrogen substitution, the reaction vessel was sealed, and the temperature was raised to 220 ℃ with stirring while maintaining the reaction vessel at 0.4 MPaG. The pressure in the reaction vessel was maintained at 0.4MPaG as it was, and the polycondensation water formed was kept for 30 minutes while being discharged to the outside of the system. The inside of the reaction vessel was slowly returned to atmospheric pressure, and then the inside of the reaction vessel was depressurized to 80kPaG using a liquid aspirator and the polycondensation water was removed. The stirring torque of the stirrer was observed when the pressure was reduced, and at the time point when the stirring torque reached a predetermined torque, the stirring was stopped, the reaction vessel was pressurized with nitrogen, the bottom discharge valve was opened, and the polymer was discharged from the strand die to form a strand, which was then cooled and pelletized by a pelletizer.

Subsequently, the pellets were put into a stainless steel rotary drum type heating apparatus and rotated at 5 rpm. Then, the inside of the reaction system was sufficiently purged with nitrogen, and the temperature was raised from room temperature (23 ℃) to 150 ℃ under a small nitrogen gas flow. When the temperature in the reaction system reached 150 ℃, the pressure was reduced to 1torr or less, and the temperature in the reaction system was further increased to 190 ℃ over 110 minutes. The solid-phase polymerization was continued at the same temperature for 90 minutes from the time point when the temperature in the reaction system reached 180 ℃. After the completion of the reaction, the pressure reduction was stopped, the temperature in the reaction system was lowered under a nitrogen gas stream, and the particles were taken out at a time point at which 60 ℃ was reached, whereby a polymer compound as a-aminocaproic acid unit: hexamethylene adipamide unit 70: 30 mol% of an aliphatic polyamide (B2) (polyamide 6/66) (relative viscosity: 4.1, melting point: 184.3 ℃ C.).

As the other aliphatic polyamide (B), the lubricant, the nonionic surfactant and the compatibility inhibitor, the following were used.

Aliphatic polyamide (B1): polyamide 6/66 "Novamid 2030 FC" (manufactured by DSM Co., Ltd. -aminocaproic acid unit: hexamethylene adipamide unit: 85: 15 (mol%), relative viscosity: 4.1, melting point: 199.0 ℃ C.)

Aliphatic polyamide (B3): polyamide 6 "UBE Nylon 1022B" (manufactured by Yu Yongshi Co., Ltd., relative viscosity: 3.5, melting point: 225.0 ℃ C.)

Lubricant (L1): calcium stearate "Calcium stearate S" (manufactured by Nichiyu oil Co., Ltd., fine powder)

Lubricant (L2): ethylene bis stearamide "ALFLOW H-50S" (manufactured by Nichikoku K.K., average particle diameter: 190 μm)

Nonionic surfactant: polyoxyethylene sorbitan monolaurate "Nonion LT-221" (manufactured by Nichio oil Co., Ltd.)

Compatible inhibitor (S1): calcium hydroxide

Compatible inhibitor (S2): sodium acetate

(non-stretching film)

Example 1

After replacement with nitrogen gas using a drum mixer, the m-xylylene group-containing polyamide (a1) and the aliphatic polyamide (B1) were charged into an apparatus at a mass ratio of 60/40 (a1)/(B1), and mixed while flowing nitrogen gas, to prepare a dry-blended mixture.

Using a single-screw film production apparatus equipped with a 2-axis full-flight screw having a diameter of 25mm, a feedblock, a T die, a chill roll, a winder and the like, dry-blended pellets having a mass ratio (A1)/(B1) of m-xylylene group-containing polyamide (A1) to aliphatic polyamide (B1) of 60/40 were fed into an extruder and extruded at 15rpm and 255 ℃ to obtain a non-stretched film having a thickness of 30 μm. The residence time of the dry-blended pellets in the extruder at this point was about 6 minutes. The obtained film was subjected to DSC measurement, tensile mechanical properties, OTR, HAZE and YI measurement. The results are shown in Table 1.

Example 2

A non-stretched film was produced in the same manner as in example 1 except that the temperature of the extruder was 265 ℃. The results are shown in Table 1.

Example 3

A non-stretched film was produced in the same manner as in example 1 except that the m-xylylene group-containing polyamide (a2) was used in place of the m-xylylene group-containing polyamide (a1), and various evaluations were performed. The results are shown in Table 1.

Example 4

A non-stretched film was produced in the same manner as in example 1 except that the m-xylylene group-containing polyamide (A3) was used in place of the m-xylylene group-containing polyamide (a1), and various evaluations were performed. The results are shown in Table 1.

Comparative example 1

A non-stretched film was produced in the same manner as in example 1 except that dry-blended pellets in which the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) was 70/30 were used, and various evaluations were performed. The results are shown in Table 1.

Comparative example 2

A non-stretched film was produced in the same manner as in example 1 except that dry-blended pellets in which the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) was 50/50 were used, and various evaluations were performed. The results are shown in Table 1.

Comparative example 3

A non-stretched film was produced in the same manner as in example 1 except that an aliphatic polyamide (B2) was used in place of the aliphatic polyamide (B1), and various evaluations were performed. The results are shown in Table 1.

Comparative example 4

A dry-blended pellet having a mass ratio (A1)/(B1) of m-xylylene group-containing polyamide (A1) to aliphatic polyamide (B1) of 60/40 was melt-mixed using a 37 mm-diameter twin-screw extruder "TEM-37 BS" (manufactured by Toshiba mechanical Co., Ltd.) under conditions that the extrusion temperature became 255 ℃ (set temperature: 250 ℃, screw rotation speed: 150rpm), and then extruded into a strand, cooled and pelletized by a pelletizer. The residence time at this point was about 3 minutes. The pellets obtained by melt-mixing were vacuum-dried at 140 ℃ for 5 hours in a vacuum dryer, and then a non-stretched film was produced in the same manner as in example 1, and various evaluations were carried out. The results are shown in Table 1.

Comparative example 5

The m-xylylene group-containing polyamide (A1) and the aliphatic polyester were subjected to extrusion at 295 ℃ under conditions of a set temperature of 300 ℃ and a screw rotation speed of 100rpmDry-blended pellets having a mass ratio (A1)/(B1) of amide (B1) of 60/40 were used

The resulting mixture was melt-mixed in a twin-screw extruder "TEM-37 BS" (manufactured by Toshiba mechanical Co., Ltd.), extruded into a strand, cooled, and pelletized by a pelletizer. The residence time at this point was about 5 minutes. The pellets obtained by melt-mixing were vacuum-dried at 140 ℃ for 5 hours in a vacuum dryer, and then a non-stretched film was produced in the same manner as in example 1, and various evaluations were carried out. The results are shown in Table 1.

Comparative example 6

A non-stretched film was produced in the same manner as in example 1 except that an aliphatic polyamide (B3) was used in place of the aliphatic polyamide (B1), and various evaluations were performed. The results are shown in Table 1.

Comparative example 7

A non-stretched film was produced in the same manner as in example 1 except that only the m-xylylene group-containing polyamide (a1) was used without blending, and various evaluations were performed. The results are shown in Table 1.

Comparative example 8

A non-stretched film was produced in the same manner as in example 1 except that only the aliphatic polyamide (B1) was used without blending, and various evaluations were performed. The results are shown in Table 1.

[ Table 1]

*1cc·mm/(m²Tian-atm)

Dry: dry blending

Melt mixing of Melt

In comparative example 7 using only the m-xylylene group-containing polyamide (A1), the film had poor elongation. In comparative example 8 using only the aliphatic polyamide (B1), the tensile elastic modulus and the gas barrier property were poor. In comparative examples 4 and 5 in which pellets obtained by previously melt-mixing a polyamide (a1) containing m-xylylene and an aliphatic polyamide (B1) were further melt-molded, the tensile mechanical properties and the gas barrier properties were insufficient. An aminocaproic acid unit was used: hexamethylene adipamide units are not contained in the aliphatic polyamide (B2) in comparative example 3 defined in the present invention, and the gas barrier properties are insufficient. In comparative example 6 using an aliphatic polyamide (B3) in which the aliphatic polyamide is composed of only aminocaproic acid units, the gas barrier properties were not sufficient, and the moldability was poor because the crystallization rate was too high. In addition, in comparative example 1 in which the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) was 70/30, the elongation of the film was insufficient, and in comparative example 2 in which the mass ratio (a1)/(B1) was 50/50, the gas barrier property was insufficient.

In contrast to these results, examples 1to 4 using the dry-blended mixture of the present invention are excellent in gas barrier properties, transparency and toughness.

(multilayer film)

Example 5

Using a multilayer film molding apparatus comprising a first extruder having a diameter of 32mm, second to fourth extruders having a diameter of 40mm, a feed block, a T die, a chill roll and a film puller, dry-blended pellets having a mass ratio (A1)/(B1) of m-xylylene group-containing polyamide (A1) to aliphatic polyamide (B1) as a gas barrier layer of 60/40 were extruded from the first extruder at an extrusion temperature of 255 ℃, maleic anhydride-modified polypropylene "MODIC P604V" (manufactured by Mitsubishi chemical Corporation) as an adhesive layer (AD) was extruded from the second extruder at an extrusion temperature of 210 ℃, homopolypropylene "NOVATEC FY 6" (manufactured by Japan Corporation) as a polypropylene layer (PP) was extruded from the third extruder and the fourth extruder at an extrusion temperature of 240 ℃, the feed block and the T die were set to 255 ℃ to obtain 3 multilayer films having a total thickness of 200 μm and comprising PP/AD/gas barrier layer/AD/PP and 3 layers A film. The residence time at this point was about 5 minutes. The thickness distribution of each layer of the multilayer film was 80/10/20/10/80(μm) in terms of PP/AD/gas barrier layer/AD/PP.

The total thickness of the multilayer film and the ratio of the layers were measured by cutting the multilayer film with a cutter and measuring the cross section with an optical microscope.

The film thus produced was subjected to morphological observation, tensile mechanical properties, OTR, HAZE and YI measurement. The results are shown in Table 2. From the results of morphological observation of the gas barrier layer, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 140nm, the MD length of the columnar domains was larger than the TD length, and the MD average length of the columnar domains was 850 nm.

Example 6

In the production of a multilayer film, as a gas barrier layer: a multilayer film was produced in the same manner as in example 5 except that 300 mass ppm of the lubricant (L1) and 100 mass ppm of the nonionic surfactant were added to 100 mass parts of the dry-blended pellets in which the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) (60/40), and various evaluations were performed. The results are shown in Table 2. From the results of morphological observation, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 150nm, the MD length of the columnar domains was longer than the TD length, and the MD average length of the columnar domains was 800 nm.

Example 7

The amount of the lubricant (L1) was changed to 2000 mass ppm with respect to 100 parts by mass of the dry-blended particles; a multilayer film was produced in the same manner as in example 5 except that the amount of the nonionic surfactant was changed to 100 mass ppm, and various evaluations were performed. The results are shown in Table 2. From the results of morphological observation, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 120nm, the MD length of the columnar domains was longer than the TD length, and the MD average length of the columnar domains was 720 nm.

Example 8

A multilayer film was produced in the same manner as in example 7 except that the lubricant (L2) was used in place of the lubricant (L1), and various evaluations were performed. The results are shown in Table 2. From the results of morphological observation, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 130nm, the MD length of the columnar domains was longer than the TD length, and the MD average length of the columnar domains was 770 nm.

Example 9

In the production of a multilayer film, as a gas barrier layer: a multilayer film was produced in the same manner as in example 5 except that 1000 mass ppm of the compatibility inhibitor (S1) was added to 100 mass parts of the dry-blended pellets in which the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) (a1)/(B1) was 60/40, and various evaluations were performed. The results are shown in Table 2. From the results of morphological observation, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 130nm, the MD length of the columnar domains was longer than the TD length, and the MD average length of the columnar domains was 780 nm.

Example 10

In the production of a multilayer film, as a gas barrier layer: a multilayer film was produced in the same manner as in example 6 except that 500 mass ppm of the compatibility inhibitor (S2) was added to 100 mass parts of the dry-blended pellets in which the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) (a1)/(B1) was 60/40, and various evaluations were performed. The results are shown in Table 2. From the results of morphological observation, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 130nm, the MD length of the columnar domains was longer than the TD length, and the MD average length of the columnar domains was 790 nm.

Example 11

A multilayer film was produced in the same manner as in example 10 except that the amount of the compatibility inhibitor (S2) was changed to 1000 mass ppm based on 100 parts by mass of the dry-blended pellets, and various evaluations were performed. The results are shown in Table 2. From the results of morphological observation, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 130nm, the MD length of the columnar domains was longer than the TD length, and the MD average length of the columnar domains was 780 nm.

Example 12

A multilayer film was produced in the same manner as in example 10 except that the amount of the compatibility inhibitor (S2) was changed to 2000 mass ppm based on 100 parts by mass of the dry-blended pellets, and various evaluations were performed. The results are shown in Table 2. From the results of morphological observation, it was found that a microphase-separated structure was formed, the microphase-separated structure was a columnar structure comprising an aliphatic polyamide (B1), the average diameter of the columnar domains was 120nm, the MD length of the columnar domains was longer than the TD length, and the MD average length of the columnar domains was 770 nm.

Comparative example 9

A multilayer film was produced in the same manner as in example 5 except that the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) used in comparative example 4 was 60/40 melt-mixed pellets as a gas barrier layer, and various evaluations were performed. The results are shown in Table 2.

The resin pressure in the first extruder into which the melt-mixed pellets of the m-xylylene group-containing polyamide (a1) and the aliphatic polyamide (B1) were charged was unstable, and only a locally stable film was obtained. In addition, as a result of morphological observation, the m-xylylene group-containing polyamide (a1) and the aliphatic polyamide (B1) were compatible.

Comparative example 10

A multilayer film was produced in the same manner as in example 5 except that melt-mixed pellets in which the mass ratio (a1)/(B1) of the m-xylylene group-containing polyamide (a1) to the aliphatic polyamide (B1) used in comparative example 5 was 60/40 were used as a gas barrier layer in the production of the multilayer film, and various evaluations were performed. The results are shown in Table 2.

The resin pressure in the first extruder into which the melt-mixed pellets of the m-xylylene group-containing polyamide (a1) and the aliphatic polyamide (B1) were charged was unstable, and only a locally stable film was obtained. In addition, as a result of morphological observation, the m-xylylene group-containing polyamide (a1) was compatible with the aliphatic polyamide (B1).

Comparative example 11

A multilayer film was produced in the same manner as in example 5 except that only m-xylylene group-containing polyamide (a1) was used as a gas barrier layer in producing the multilayer film, and various evaluations were performed. The results are shown in Table 2.

Comparative example 12

A multilayer film was produced in the same manner as in example 5 except that only aliphatic polyamide (B1) was used as a gas barrier layer in producing the multilayer film, and various evaluations were performed. The results are shown in Table 2.

Comparative example 13

A multilayer film was produced in the same manner as in example 5 except that only EVOH "EVAL J102B" (manufactured by Kuraray co.ltd., ethylene content 32 mol%) was used as a gas barrier layer in producing the multilayer film, and various evaluations were performed. The results are shown in Table 2.

[ Table 2]

In comparative example 11 in which only the m-xylylene group-containing polyamide (a1) was used as the gas barrier layer, the elongation of the film was poor. In comparative example 12 in which only the aliphatic polyamide (B1) was used as the gas barrier layer, the gas barrier property was poor. In comparative example 13 in which only EVOH was used, the film had poor elongation. In comparative examples 9 and 10 using pellets obtained by melt-mixing a polyamide (a1) containing m-xylylene and an aliphatic polyamide (B1), the gas barrier properties were insufficient.

On the other hand, examples 5 to 12 using the dry-blended mixture of the present invention are excellent in gas barrier properties, transparency and toughness.

Example 13

Using a multilayer film forming apparatus comprising a first extruder having a diameter of 32mm, second to fourth extruders having a diameter of 40mm, a feed block, a T die, a cooling roll and a film puller, extruding dry-blended pellets of a mass ratio (A1)/(B1) of m-xylylene group-containing polyamide (A1) to aliphatic polyamide (B1) as a gas barrier layer of 60/40 from a first extruder at an extrusion temperature of 260 ℃, "MODIC M545" (manufactured by Mitsubishi chemical Co., Ltd.) as an adhesive layer (AD) was extruded from a second extruder at an extrusion temperature of 230 ℃, "novatell UF 240" (manufactured by Japan Polyethylene Corporation) as a Linear Low Density Polyethylene (LLDPE) was extruded from the third and fourth extruders at an extrusion temperature of 230 ℃, and the feed head and T-die temperatures were set to 255 ℃ to obtain an unstretched multilayer film comprising 3 kinds of 5 layers of a total thickness of 150 μm of a gas barrier layer/AD/LLDPE layer. The residence time at this point was about 4 minutes.

The obtained unstretched laminated film was held at a preheated blowing temperature of 140 ℃ for 30 seconds by a clip-type simultaneous biaxial stretcher, then stretched 2 times in the longitudinal axis direction and 2 times in the transverse axis direction, and the ends of the film were held on a tenter device and heat-set at 105 ℃ for 30 seconds in a tenter oven. The thickness distribution of each layer of the stretched multilayer film was 6/5/6/5/15(μm) in terms of gas barrier layer/AD/LLDPE layer.

The obtained multilayer stretched film is excellent in the balance between gas barrier properties and flexibility. Further, the multilayer stretched film can be kept low in shrinkage rate during storage and after boiling, and exhibits sufficient shrinkability during heat shrinkage by heat treatment.

[ Table 3]

Industrial applicability

By molding the dry-blended mixture of the present invention, a polyamide film excellent in gas barrier properties, transparency and toughness can be provided.

Claims

1. A dry-blended mixture of (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide, wherein the mass ratio ((A)/(B)) of the (A) polyamide containing m-xylylene to the (B) aliphatic polyamide is in the range of 55/45 to 65/35,

2. The dry mix as claimed in claim 1, wherein the melting point peak (Tm (A, M)) of the M-xylylene group-containing polyamide (A) measured by differential scanning calorimetry and the melting point (Tm (A)) of the M-xylylene group-containing polyamide (A) before dry mixing measured by differential scanning calorimetry satisfy the following relationship (1), and the melting point peak (Tm (B, M)) of the aliphatic polyamide (B) measured by differential scanning calorimetry and the melting point (Tm (B)) of the aliphatic polyamide (B) before dry mixing measured by differential scanning calorimetry satisfy the following relationship (2),

Tm(A)-3≤Tm(A，M)≤Tm(A) (1)

Tm(B)-3≤Tm(B，M)≤Tm(B) (2)。

3. the dry-blended mixture according to claim 2, wherein the melting point peak (Tm (A, M)) of the (A) M-xylylene group-containing polyamide is in the range of 225 to 237.5 ℃ and the melting point peak (Tm (B, M)) of the (B) aliphatic polyamide is in the range of 195 to 199 ℃.

4. The dry-blended mixture according to any one of claims 1to 3, wherein the difference between the relative viscosity of (A) the m-xylylene group-containing polyamide and the relative viscosity of (B) the aliphatic polyamide is in the range of 0.6 to 1.6.

5. The dry blend mixture according to any one of claims 1to 3, further comprising 300 to 4000 ppm by mass of a compatibility inhibitor with respect to 100 parts by mass of the total amount of the (A) m-xylylene group-containing polyamide and the (B) aliphatic polyamide.

6. The dry mix mixture as claimed in claim 5, wherein the compatibility inhibitor is at least 1 selected from the group consisting of sodium acetate and calcium hydroxide.

7. A dry mix as claimed in any one of claims 1to 3, comprising: ethylene bis (stearamide) or calcium stearate 100 to 4000 mass ppm and a nonionic surfactant 30 to 800 mass ppm,

8. A method for producing a dry-blended mixture, which comprises a step of dry-blending particles of (A) a metaxylylene group-containing polyamide and particles of (B) an aliphatic polyamide in such a manner that the mass ratio ((A)/(B)) of the metaxylylene group-containing polyamide to the aliphatic polyamide (B) is in the range of 55/45-65/35,

9. The method for producing a dry blended mixture according to claim 8, wherein in the step of dry blending, 300 to 4000 ppm by mass of a compatibility inhibitor is added to 100 parts by mass of the total amount of the (A) m-xylylene group-containing polyamide and the (B) aliphatic polyamide.

10. The method for producing a dry-blended mixture according to claim 8 or 9, comprising the following steps after the step of performing dry blending: 30 to 800 ppm by mass of a nonionic surfactant is added to 100 parts by mass of the total amount of (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide, and then 100 to 4000 ppm by mass of ethylene bis (stearamide) or calcium stearate is added to 100 parts by mass of the total amount of (A) a polyamide containing m-xylylene and (B) an aliphatic polyamide.

11. A molded article of a dry-blended mixture, wherein a microphase-separated structure is present in a molded article obtained by melt-blending the dry-blended mixture according to any one of claims 1to 7.

12. Molded body of a dry-blended mixture according to claim 11, wherein the microphase-separated structures are columnar structures,

the columnar domains of the columnar structure are (B) aliphatic polyamide,

the diameter of the columnar crystal domain is 100 to 200nm,

the MD length of the columnar crystal domain is longer than the TD length,

the average MD length of the columnar crystal domains is 200nm to 3 μm,

the MD length and TD length were determined by morphological observation using FE-SEM.

13. A film or sheet comprising a layer formed from the dry blended mixture of any one of claims 1to 7.